Commercial air transport aircraft are equipped with multiple (3) fully functioning very high frequency (VHF) range radios to provide for voice and short-message data communication between the pilots and ground based air traffic controllers, and/or airline-dispatch-operation controllers when flying overland. Similarly multiple (2) high frequency (HF) range radios and a multi-channel (4) satellite communication (SATCOM) radio provide for voice and data communications between the pilots and ground controllers when flying over oceanic routes or remote areas where VHF radio coverage is not available. An avionics data communications router (ACR) on board the aircraft manages the down linking of data messages over the appropriate communications link based on link availability and routing policies. The avionics data communications router also manages the delivery of data received via any of the radio communications links to the appropriate end system on board the aircraft.
Similarly an audio management unit (AMU) switches/routes the voice audio received over a selected VHF, HF or SATCOM radio channel to the appropriate headset and/or speaker in the cockpit. The audio management unit also switches/routes the microphone audio to the selected VHF, HF or SATCOM radio. Up to 3 radio control panels (RCP) in the cockpit are operable to select the mode of operation (voice or data) and the operating frequency of the 3 VHF radios and 2 HF radios when voice mode is selected. The radio control panels are also operable to select the “called party” telephone number when a voice call is to be placed over one of the SATCOM radio voice channels. Similarly 3 or more audio control panels in the cockpit are operable to select the VHF, HF or SATCOM radio whose voice audio output is to be switched/routed to a particular headset/microphone audio jack or speaker in the cockpit. The control/selection functions performed by a radio control panel and an audio control panel may be combined into a single radio management panel (RMP). The number of line replaceable units (also referred to herein as “boxes”) required to provide this capability is relatively high and drives up the cost, weight, and volume of the system. The inter-wiring between the boxes adds to the weight of the system and the more wiring there is, the greater the complexity and cost of installing the system. Fewer boxes and simpler inter-wiring is desirable.